Speaker shock absorbers


From time to time people have posted different methods for mechanically decoupling their speakers from the floor to reduce vibration. Some of these have involved using a ply system of rubber strips and wood strips, which seems reasonable to me. I have looked for suitable sized sections of rubber or even for large sheets to cut up but have been unsuccessful. To those who have used that method -where did you find the material and what thickness of rubber and wood did you use for each layer - finally how many layers did you end up using?
musicnoise
If you have a rigid box speaker it becomes less of an issue but I find blu-tak and rubber pads and thick felt (like for furniture) work very well. If you need to resort to ply and rubber layers then it is probably worth considering a speaker upgrade to something that does not have so much cabinet waffle. (you can usually tell a good speaker by tapping and trying to lift it - if you can't lift it then that is often a good sign - if you can cary it with one hand then you will likely have a problem)
Musicnoise - I use Vibrapods. I placed one under each corner. They cost $5 a piece in weight ranges 1-5. I have 5s at the front (heavier) and 4s under back corners. It was one of the best things I bought. Bass became short well control and very even - proper word would be "musical". The only disadvantage is that speakers are not standing as rigidly as before - wobble a little when I push them. It might be a concern with small children running.
For a cheap alternative, try your local hardware store. Rubber grommets, o-rings, and various rubber thingies (technical term) in the plumbing department can give you a low-cost way to try various decoupling/resonance damping schemes. I've found all kinds of different thicknesses (or double up with several) and levels of squishiness (another technical term). Good luck, Dave
Well, I can recommend Hockey pucks, a very hard rubber, that I think has worked for me. Cheap! And will maintain speakers inherrent stability.

Now for something a bit more absorbent, are sheets of heavy rubber pads, made I think from recycled rubber, which are primarily intended for garage floors. Very dense and heavy. Trimmed to the size of the bottom of your speaker I doubt that they would alter the stability of the speaker and I'm confident they would be great for isolation in a speaker/floor interface. FWIW, I've started using sheets of this stuff under components which don't use bottom ventilation. So far as I can tell it works very well (I've used sorbothane in the past, and still do).
I got mine from Home Depot - cost about $35 for 6 18" squares (I trim of the interlocking tabs and end up with 14" squares).

FWIW.
As to weight of the speakers - they are 90 lbs each. The vibration is not bad - the speaker cabinet does not noticably vibrate. But, at 105 db peaks with my feet on the carpeted wooden floor, sitting 6 feet away, I can feel the base. It seems to me that completely eliminating any transmission along the floor would be ideal. I cannot imagine that this would not occur in even the heaviest of speakers without decoupling. The garage rubber pads sound like just the ticket - I'll check out home depot - the hocky pucks are also an interesting idea.
Musicnoise, some of what you are feeling is the result of airborne bass soundwaves, not necessarily as a result of the speaker/floor interface. And airborne soundwaves, especially bass ones are tough to deal with unless you have sound absorbers of some sort in the room, the the sound absorbers for bass would have to be huge. FWIW.
Musicnoise - hockeypucks might be to hard. Vibrapods are constructed of special rubber specially for that purpose. My speakers are also around 90 lbs and very rigid - (a lot of cross boards inside) but floor is not (basement). Originally I had spikes. Idea of the spike is that infinitely small point cannot transfer energy. In practice it does but shifts resonance frequency up. Regular rubber bounces and felt compresses. Rubber and construction of vibrapods create big losses (no energy transfer). Similar rubber is used in pro computers to isolate drive cage from the rest of the computer. The best is to use softer vibrapods and more of them but it costs.
newbee - I agree with that statement. It appears that you are in sync with the effect that I was trying to control. It had occurred to me that some of what I was feeling was due to the sound wave without interaction with the floor. I do not necessarily want to eliminate that effect. My only goal is to get rid of any transmission that is not airborne so to speak. As to sound traps in the room, I have several in place, the goal of which was to reduce the liveliness of the room which, without the sound traps ends up reinforcing the high frequencies - those have worked well for that purpose.
I have had great success with "Unhappy Balls". They work in this application to 1) absorb vibration 2) do so while remaining stiff. Halve the large size (1-1/2" Diameter) ones for a secure fit. http://scientificsonline.com/product.asp_Q_pn_E_3039129
I do not necessarily want to eliminate that effect. My only goal is to get rid of any transmission that is not airborne so to speak.

Heavy underlay with heavy carpet on top is by far your best bet. Try to dampen the entire surface rather than just the interface beneath the speakers.
If you have to go upscale, as I did, you might like to know that Herbie's Grounding Bases worked very well under my spiked floorstanders... at a price.
Why aren't you using spikes? Do you imagine most speaker manufacturers include them for decoration?
Spikes actually 'decouple' the speakers from the low-frequency structure-bourne feedback able to be carried in most timber-framed floors. These large-wavelength low frequencies are unable to 'cross-over' the tiny contact points of the spikes. Any rubber or foam you introduce between the floor and the speakers will simply ' bounce' with the feed-back induced movement of the floor and if anyone out there considers 'moving' speakers to be a good thing, they may not be the best people to listen to?
Halcro - I am well aware of spikes and have used them - that was not my question - your answer is non-responsive to my question and, hence both irrelevant and of without value to me. My question was simply where people who had used the method that I described found their materials. If I cared about what someone thought of my proposed method I would have asked a different question.
I've a pair of DIY "minitowers" at the crossover design stage and will place them atop stereo subs. While I don't listen at high volumes, absorbing any sub vibrations is a concern. I bought two sorbothane sheets (which cover the entire bases of the towers) from Edmund Scientific for decoupling. Of course the clear plastic protective sheeting on either side of the sorbothane will stay in place so as not to ruin the veneers with "sorboleak". We'll just have to see if it does the trick...
The Equarack footers would be perfect. I'm using them under a large subwoofer to isolate it from the floor and the surrounding electronics. Dramatically effective. Works better than any other homebrew or store bought remedies that I've tried. Gets rid of false resonant information from the sub. Increases real definition and eliminates resonant contamination bleeding through to the electronics. Sounds like this is pretty much what you need.
Maybe my experience can illuminate the question whether to spike or not. During a long audiophile life I have vacillated between spikes or more pliant shock absorbers (SD-feet from Sweden, the Base Platform from Norway and Valhalla Technology from Denmark). All had their advantages, but the main problem was that they made the speakers wobbly and the sound muddy. So I always returned to spikes. So a few weeks ago I by chance discovered Equarack speaker mounts (from the US). I ordered eight of these and put four under each of my Vienna Acoustics Beethoven Concert Grand speakers. Suddenly everything fell into place: natural, smooth, free flowing music but with tight bass and sharp transients. I can`t recommend them highly enough ( I am certainly not paid by the producer to say this!). So this might be the "final solution"! So try them.
Trondf - Have you tried Vibrapods. It is pretty much the same idea (lossy viscoelstic rubber) and very smart design. I have one of them under each corner of my speakers. Compare to spikes sound is cleaner, bass is faster and more even/musical.
Vibrapods are perhaps not as good as Equarack speaker mounts but my total bill was about $50 while Equaracks would cost me over $1400.
Kijanki - No I haven`t tried the Vibrapods. To me they seem to be based on more or less the same principles as the products I have tried before, but then again: I don`t know too much about them. Anyhow, they seem to work for you and that is the main thing. As to the cost of the Equarack speaker mounts: 8 mounts with viscoelastic pellets set me back around 6-700 US dollars. For me they combine two things: stability and decoupling/isolation. But the real proof is in the pudding; i.e. listening. What sounds good to you is good, isn`t it?
Trondf - It sounds better than spikes by cutting off resonanses of the floor (basement underneath). The question is how much better it could sound with Equaracks. My modest speakers are around 90lbs each and Equarack footers for this range are $160 each + $18 for bag of 10 rubber pellets (from their web page). Total amount for whole set is pretty much what I paid for the speakers. Vibrapods have poor stability - speakers are straight but wobble a little when pushed. If Equarcks are more stable I might invest one day in them, when I get better speakers. What I like about them is ability to adjust load by inserting different amount of pellets - Vibrapods have to be ordered in different load ranges.
Hi Kijanki,

I believe Trondf meant the SM-1 model($70 w/ 50lbs capacity ea), not the SM-2 which you mentioned @ $160ea (150lbs capacity). So, $80 (w/ $10/ pack of pellets)x 8(4/spkr) = $640.00. Still, this is not insubstantial but if you have the dough, its justifiable.

Kenobi
Kenk168 - Thank you. I read it as a weight of the speaker and not the load on each footer. $640 sounds much better.

Trondf - how stable are the speakers (how much rubber gives). Vibrapods are designed as pads of special lossy rubber without hard limit. Equaracks seems to have hard limit created by metal parts. Am I right?
On the topic of Vibrapods. You pick them based on the weight they are to carry. If you want the speakers to be stiffer and the sound tighter, you can just increase the number of pods under each speaker.

Under my monitors (four #2 vibrapods under each speaker) they are just the ticket. Richer, livelier and more musical than spikes, cones, or absorbant pads, and with nearly equal clarity. No downside at all.

Under my floorstanders (using five #4 'pods), the sound is very rich and warm, with a clear top end. Bass is looser, but I still prefer to the factory spikes due to the wonderful rich tone.

I tried four #5 vibrapods, but I lost some warmth and switched back to the #4.
Ssglx - I use 5s under front and 4s under rear. I remember from their website that it's better to use few of the low number instead of one of the higher number. I consider putting speakers back on the spikes on oversized granite slab/tile and a lot of #1 vibrapods between tile and the floor. Equaracks might provide better stability and better damping characteristic. I don't mind spending more on non-perishable items like cables or footers.
Interesting thread.

My 150 lb speakers are on spike, but instead of sitting on carpet directly I found the sound to be better sitting on a 1/2" granite between spike and carpet. I used the granite which was left over from my house remodel for ease of moving the speakers initially, but after hearing what they do I left them under the speakers.

I am ready to try something like Symposium platform under the speakers, but I agree spikes should still be used regardless what you put under.
This is a bit older thread, but I thought I'd report some successful findings.

A few months ago I aquired a pair of Soliloquy 5.3i floorstanders. Great speakers! I'd been trying several types of footers to get the best balance, musicality, clarity, and bass.
With my older Soliloquy monitors it was no contest. Vibrapods hands down for clarity and great tone, exceptional liveliness, and even a little bass boost and growl.
With the floorstanders I tried several variations of vibrapods, different configurations and ratings (#4's and #5's). I got the clarity, tone and musicality I wanted, but the bass was always just a step behind the music and a little sloppy.
Another product I'd tried with the monitors are a cork and rubber product called Isol-Pads available here on Audiogon. They did a good job of decoupling the monitors but lightened the bass unacceptably. On the floorstanders however they have been great! Clarity is still good, the sound is very clean and musical and now the PRAT is back. Bass is appropriately quick and even, and still with satisfying weight. Low level liveliness is good, much better than on spikes, but not quite up to the more energy preserving vibrapods.
I would encourage anyone who wants to try decoupling their floorstanders to try the Isol-pad product. They are not at all expensive.

Chris
I have never tried these, but...Meade and other telescope manufacturers make isolation pads designed to go under tripod feet, sold in 3 piece sets.
Lots of industrial isolation pads available if you google.